Rotary mining tool retaining structure

ABSTRACT

A mining tool of the type in which a pick style bit is rotatably mounted in a bore in a support member and is retained therein by retaining means integrally formed on the bit. The retaining means advantageously takes the form of at least one radial projection on the rear end of the bit shank with the bit shank being slotted to impart radial resilience thereto so the bit can be assembled with the support member and readily disassembled therefrom while being retained therein during work operations. The support member may comprise a support block adapted for being fixed to a driver with a sleeve rotatable in a bore in the block and, in turn, rotatably receiving the bit. The sleeve may be slotted axially from the rear end so as to have lateral resilience and be formed with one or more radial projections or protrusions at the rear end so that the sleeve, also, is releasably retained in the block by retaining means integral therewith.

United States Patent [1 1 Crosby Feb. 11, 1975 ROTARY MINING TOOLRETAINING STRUCTURE lnventor:

U.S. Cl 299/86, 37/142 A, 175/354, 299/92, 403/165, 40/289 Int. Cl. E2lc35/18 Field of Search 299/86, 92; 403/165, 289; 175/354, 413; 37/142 A4/1967 Makinen 299/92 X 3/1970 Morrow 299/92 X Primary ExaminerErnest R.Purser [57] ABSTRACT A mining tool of the type in which a pick style bitis rotatably mounted in a bore in a support member and is retainedtherein by retaining means integrally formed on the bit. The retainingmeans advantageously takes the form of at least one radial projection onthe rear end of the bit shank with the bit shank being slotted to impartradial resilience thereto so the bit can be assembled with the supportmember and readily disassembled therefrom while being retained thereinduring work operations. The support member may com prise a support blockadapted for being fixed to a driver with a sleeve rotatable in a bore inthe block and, in turn, rutatahly receiving the bit. The sleeve may beslotted axially from the rear end so as 10 have lateral resilience andbe formed with one or more radial projections or protrusions at the rearend so that the sleeve, also, is releasably retained in the block byretaining means integral therewith.

11 Claims, 8 Drawing Figures PATENTEDFEWQ Y 3,865,437

SHEET 20F 2 ROTARY MINING TOOL RETAINING STRUCTURE The present inventionrelates to mining tools and is particularly concerned with a retainingarrangement for use in retaining pick style bits in supporting memberstherefor and, also for retaining parts of a supporting member, such as asleeve and block, in assembled relation.

Pick style mining tools are well known, and it is also well known tosupport such a mining tool in a support member so that the mining toolis free to rotate in the support member and thereby to remain sharpduring continued use thereof.

I-Ieretofore, the tools have been held in assembled relation either byseparate keeper elements that are driven into the assembly of the bitand support member after assembly thereof, or by separate keeperelements which are mounted in grooves formed in the shanks of the bits.

Further, the support member is such a bit can take the form of a boredblock having a sleeve rotatable in the bore and with a bit rotatablymounted in the sleeve. Heretofore, such sleeves have also been retainedin assembled relation with the block by keeper elements separatetherefrom, and which it is required to assemble with the sleeve eitherprior to or after assembly of the sleeve in the block.

With the foregoing in mind, the primary object of the present inventionis the provision ofa pick style mining bit in which the keeper devicefor retaining the bit assembled with a supportmember is formedintegrally therewith.

Another object is the provision of a support member for a pick style bitmade up of a sleeve rotatably mounted in a block in which the retainingmeans is retaining the sleeve in the block is formed integrally with thesleeve.

BRIEF SUMMARY OF THE INVENTION According to the present invention, theshank of a mining tool, and which may be a pick style bit or a supportsleeve for the bit, is slotted axially from the rearward end to impartlateral or radial resilience to the rear end of the bit or sleeve. Theresilient portion of the bit or sleeve is then provided with one or moreradial projections or protuberances, and upon the shank of the bit, orthe sleeve, being forced into a bore until the projections register witha recess or the rear end of the bore, the bit or sleeve will bereleasably retained in the receiving bore therefor while being free torotate therein.

The exact nature of the present invention will become more clearlyapparent upon reference to the following detailed specification taken inconnection with the accompanying drawings in which:

FIG. 1 is a side view partly broken away showing a bit and blockaccording to the present invention.

FIG. 2 is a view looking in at the rear end of the bit.

FIG. 3 is a view similar to FIG. 1 but showing the bit in the process ofbeing assembled with the block.

FIG. 4 is a rear end view of a modified form which the bit can take.

FIG. 5 is a sectional view showing a bit and block according to thepresent invention with a sleeve interposed therebetween.

FIG. 6 is a fragmentary view similar to FIG. 5 but showing amodification.

FIG. 7 is a rear end view showing still another modification of the bit.

FIGIS is a fragmentary side view showing a still further modification ofthe bit.

DETAILED DESCRIPTION OF THE INVENTION In FIG. l, 10 represents a supportblock having a bore 12 extending therethrough from front to back withthe front end of the bore being formed with a flared seat 14.

Reference numeral 16 indicates a bit of a substantially conventionalshape which has a forward portion tapering into a point 18 and at whichpoint there may be inserted a hard wear resistant insert such as aninsert of cemented tungsten carbide. The bit has rearward portions inthe form of a shank 20 extending through bore 12 and at the forward endof bore 12 the bit comprises a flared region 22 which engages seat 14 atthe forward end of the bore. Region 22 forms a rearwardly facingabutment element for transmitting loads from the bit to the block.

According to the present invention, the rearward end of shank 20 isformed with one or more radial protuberances, or projections, 24. Theshank, furthermore, is axially split by the seat 26.

As will be seen in FIG. 2, the protuberances 24 are diametricallyopposed and are on a diameter at right angles to the diameter of cut 26and extend for a relatively short distance circumferentially. The slot26 permits the rearward end of shank 20 to have sufficient radialresilience that the shank of the bit can be pushed through bore 20 fromthe front end into the position in which the bit is shown in FIG. 1.

When the bit reaches this position, the legs of the shank formed by theslot 26 will spring outwardly and protuberances 24 will thereafterprevent the bit from being dislodged from the block. However, the bitcan be removed from the block by driving the bit forwardly.

FIG. 3 schematically shows the bit 16 in the process of being insertedinto the block, as indicated by arrow 28, and it will be seen that thelegs of the bit are sprung toward each other so that the protuberances24 can pass through the bore 12.

FIG. 4 shows a rear end view of a modification of the bit in which thebit is provided with four protuberances 30'distributed thereabout andtwo cuts 32 are formed in the shank of the bit at right angles to eachother. The modification of FIG. 4 works the same way as themodifications of FIGS. 1 to 3 in that the shank of the bit can bepressed into the bore in the block and, later, the bit can be pressed,or driven, out of the bore when it is desired to separate the bit fromthe block.

The protuberances 24 do not engage the rear face of the block underpressure so that the bit is free to rotate in the bore under theinfluence of working loads imposed on the bit.

It will be appreciated that with the protuberances 24 configured asshown with a rather flat angle on the rearwardly facing side, the bitcan relatively easily be inserted into the bore while the steeper angleon the forwardly facing side of the protuberances 24 prevents the bitfrom easily becoming dislodged from the bore during work operations.

FIG. 5 shows a modification in which a block 40 is provided with ashouldered bore 42 extending therethrough in which is mounted a sleeve44. Sleeve 44 has a shoulder engaging the shoulder in the block and hasa rearward end protruding from the block and formed with protuberances46. The rear end of sleeve 44 is split, or slotted, as at 48 and thesleeve can be assembled with the block in the same manner as describedin connection with the modifications of FIGS. 1 to 3.

The sleeve has a central bore 50 to receive the shank 52 of a bit 54constructed similarly to the bit of FIGS. 1 to 3. The bore 50 isprovided with an annular recess 56 to receive the protuberances 58formed on the rear end of the shank 52 of the bit and which shank isaxially split as indicated at 60.

FIG. 6 shows that the rear end of the bore 42 in block 40 could beprovided with a counterbore 62 to accommodate the rearward end of thesleeve 44 so that the protuberances 46 on the rear end of the sleeve andthe rear end of the sleeve would be disposed within the axial limits pfblock 40.

FIG. 7 is another view looking at the rear end ofa bit with the rear endof the shank 70 of the bit being provided with protuberances 72 adjacenteach of which there is formed an axial incision, or slot, 74 in the bitshanks so as to impart lateral resilience thereto to permit the bit tobe introduced into the bore of a block and removed therefrom.

FIG. 8 shows the shank 80 of a bit having protuberances 82 at the rearend of the shank and with an axial incision, or slot, 84 extendingaxially of the shank at right angles to the plane of the protuberances82.. In HO. 8, the shank 80 is provided with a transverse drilled hole86 which imparts greater resilience to the legs formed by incision, orslot, 84 for greater ease of assembling the bit with the supportingmember therefor and separating the bit therefrom.

In each case, the bit is rotatably supported in the supporting memberand can be assembled therewith by pressing or hammering the bit into thereceiving bore therefor and the bit can be removed in the same manner.However, no separate keeper elements or the like are required and theconstruction of the bit is, therefore, simpler than those arrangementsin which the bit must be provided with grooves and separate keepermembers that have to be assembled with the bit.

Modifications may be made within the scope of the appended claims.

What is claimed is:

1. An excavating tool comprising coaxial forward and rearward portionsand adapted for assembly with a support member, said forward portiontapering inwardly to a point at the front end and said rearward portionbeing substantially circular in cross section at each axial pointtherealong and adapted for being closely but freely rotatably receivedin a bore in the support member with the forward portion of the toolprotrudiing axially from the forward end of the bore and with therearward portion of the tool protruding at the rearward end from therear end of the bore, an element of abutment means on said tool adaptedfor engagement with an element of abutment means on the support memberto sustain working thrusts imposed on said tool in the rearwarddirection, said rearward portion of the tool comprising at least oneradially resilient region integral therewith near the rearward end ofsaid rearward portion, and at least one projection on the radially outerside of said radially resilient region protruding radially therefrom andadapted for engagement with the support member rearwardly of the rearend of the bore in the support member for releasably and freelyrotatably retaining the tool in assembled relation with the supportmember, said tool being drivable into and out of the bore in the axialdirection.

2. An excavating tool according to claim 1 in which said rearwardportion comprises at least one axial slot on the radially inward side ofsaid radially resilient region and extending into the rearward portionof the tool from the rear end thereof.

3. An excavating tool according to claim 1 in which at least therearwardly facing side of said projection is inclined to facilitatedriving said rearward portion in the bore in the support member.

4. An excavating tool according to claim 1 in which said rearwardportion is formed with at least one slot extending axially forwardlytherein from the rear end, the said rearward portion on at least oneradial side of the slot comprising said radially resilient region of therearward portion, said projection being formed on the radially outwardside of the radially resilient region near the rearward end thereof.

5. An excavating. t'ool according to claim 4 in which said slot is adiametral slot and the rearward portion of the tool on both sides ofsaid slot forms a said radially resilient region, and a said projectionof the radially outward side of the rearward end of each said radiallyresilient region.

6. An excavating tool according to claim 4 in which said projection iscentered in a plane perpendicular to the plane of the slot and extends ashort distance on each side of the plane.

7. An excavating tool according to claim 4 in which the end of said slotremote from the rearward end of said rearward portion is enlarged in adirection lateral to the slot.

8. an excavating tool according to claim 4 in which said slot is offsetradially from the axis of said rearward portion, and the smaller part ofthe rearward portion on the one side of said slot forming said radiallyresilient region of the rearward portion of the tool.

9. An excavating tool according to claim 1 in which said rearwardportion is formed with two intersecting slots extending axially intosaid rearward portion from the rear and dividing said rearward portioninto a plurality of parts each of which forms a said radially resilientregion and each of which has a said projection at the radially outwardside at the rear end and in about the circumferentially central region.

10. An excavating tool according to claim 1 in which said element ofabutment means on said tool comprises a shoulder formed on the tool atthe juncture of said forward and rearward portions and tapering inwardlytoward the rear.

11. a support member for supporting a tool having a pointed forwardportion and a cylindrical rearward portion with said portions beingcoaxial, said support member including a tubular sleeve having an insidediameter adapted closely but freely rotatably to receive the rearwardportion of the tool and having an outside diameter adapted rotatably tobe received in a bore in a support block, said sleeve having at leastone axial slot extending therein from the rear end and imparting radialresilience to the rear end of the sleeve, at leat one radial projectionon the outside of the sleeve at the rear end adapted for engagement withthe support block at the rear end of the bore in the support block toretain'the sleeve in assembled relation therewith while permitting thesleeve to rotate freely in the sup- 6 port block, said sleeve having arearwardly facing eleleasably retaining said tool in assembled relationwith ment of abutment means for engagement with the supsaid sleeve whilepermitting free rotation of the tool port block and a forwardly'facingelement of abutment and sleeve relatively.

means for engagement with the tool, and means for re-

1. An excavating tool comprising coaxial forward and rearward portionsand adapted for assembly with a support member, said forward portiontapering inwardly to a point at the front end and said rearward portionbeing substantially circular in cross section at each axial pointtherealong and adapted for being closely but freely rotatably receivedin a bore in the support member with the forward portion of the toolprotrudiing axially from the forward end of the bore and with therearward portion of the tool protruding at the rearward end from therear end of the bore, an element of abutment means on said tool adaptedfor engagement with an element of abutment means on the support memberto sustain working thrusts imposed on said tool in the rearwarddirection, said rearward portion of the tool comprising at least oneradially resilient region integral therewith near the rearward end ofsaid rearward portion, and at least one projection on the radially outerside of said radially resilient region protruding radially therefrom andadapted for engagement with the support member rearwardly of the rearend of the bore in the support member for releasably and freelyrotatably retaining the tool in assembled relation with the supportmember, said tool being drivable into and out of the bore in the axialdirection.
 2. An excavating tool according to claim 1 in which saidrearward portion comprises at least one axial slot on the radiallyinward side of said radially resilient region and extending into therearward portion of the tool from the rear end thereof.
 3. An excavatingtool according to claim 1 in which at least the rearwardly facing sideof said projection is inclined to facilitate driving said rearwardportion in the bore in the support member.
 4. An excavating toolaccording to claiM 1 in which said rearward portion is formed with atleast one slot extending axially forwardly therein from the rear end,the said rearward portion on at least one radial side of the slotcomprising said radially resilient region of the rearward portion, saidprojection being formed on the radially outward side of the radiallyresilient region near the rearward end thereof.
 5. An excavating toolaccording to claim 4 in which said slot is a diametral slot and therearward portion of the tool on both sides of said slot forms a saidradially resilient region, and a said projection of the radially outwardside of the rearward end of each said radially resilient region.
 6. Anexcavating tool according to claim 4 in which said projection iscentered in a plane perpendicular to the plane of the slot and extends ashort distance on each side of the plane.
 7. An excavating toolaccording to claim 4 in which the end of said slot remote from therearward end of said rearward portion is enlarged in a direction lateralto the slot.
 8. an excavating tool according to claim 4 in which saidslot is offset radially from the axis of said rearward portion, and thesmaller part of the rearward portion on the one side of said slotforming said radially resilient region of the rearward portion of thetool.
 9. An excavating tool according to claim 1 in which said rearwardportion is formed with two intersecting slots extending axially intosaid rearward portion from the rear and dividing said rearward portioninto a plurality of parts each of which forms a said radially resilientregion and each of which has a said projection at the radially outwardside at the rear end and in about the circumferentially central region.10. An excavating tool according to claim 1 in which said element ofabutment means on said tool comprises a shoulder formed on the tool atthe juncture of said forward and rearward portions and tapering inwardlytoward the rear.
 11. a support member for supporting a tool having apointed forward portion and a cylindrical rearward portion with saidportions being coaxial, said support member including a tubular sleevehaving an inside diameter adapted closely but freely rotatably toreceive the rearward portion of the tool and having an outside diameteradapted rotatably to be received in a bore in a support block, saidsleeve having at least one axial slot extending therein from the rearend and imparting radial resilience to the rear end of the sleeve, atleat one radial projection on the outside of the sleeve at the rear endadapted for engagement with the support block at the rear end of thebore in the support block to retain the sleeve in assembled relationtherewith while permitting the sleeve to rotate freely in the supportblock, said sleeve having a rearwardly facing element of abutment meansfor engagement with the support block and a forwardly facing element ofabutment means for engagement with the tool, and means for releasablyretaining said tool in assembled relation with said sleeve whilepermitting free rotation of the tool and sleeve relatively.